1. Field of the Invention
The present invention relates to machine tools for shaping a work piece, and more particularly to rotatable tools of the type provided with cutting inserts. Orientation of inserts on the tool is varied to avoid repetitive orientation which may promote vibrational harmonics during operation.
2. Description of the Related Art
Machining work pieces by rotary cutting tools may cause objectionable vibrational harmonics to occur. This results in chatter and other phenomena which may cause flaws in the machined product. It is not desirable to alter rotational speeds of a machine tool and rate of advance speeds of a cutting tool as such steps may interfere with optimal productivity. It is known to vary circumferential spacing of inserts and their pockets in a rotary cutting tool to break up harmonics which might otherwise occur. This approach is shown in U.S. Pat. Nos. 4,092,082, issued on May 30, 1978, to Severson. It is also known to vary rake angles among inserts, as shown in U.S. Pat. No. 4,844,666, issued on Jul. 4, 1989, to Tsujimura et al., and 5,913,644, issued on Jun. 22, 1999, to DeRoche et al., of common ownership with the present application. The prior art does not show or suggest the novel combinations of insert orientation within a rotary cutting tool as claimed.